iPod iPod Nano 7th gen: Nike+ app - how does it work?

The Nano uses a built in pedometer to measure distance. Everything else, pace, calories and such are all determined from that data and time on run.

I use the 6th gen and found it to be pretty accurate. The best placement for accuracy (on the 6th gen anyway) is on the hip. I am not sure about the 7th gen Nano.

It's best to run a known distance and a steady pace, then at the end of the run you will have the option to calibrate and set the actual distance. Do this as often as you like to "train" your Nano. I did mine maybe a half dozen times on various runs. Each calibration helps the overall accuracy. (Note that if no calibration option appears it means your pace was not steady enough.)

The app uses the run times with your distance to generate your pace per mile. As far as calorie counts, well I can't say how accurate it may or may not be. I assume it uses your height/weight data, pace, distance & time in a basic formula to generate that amount. I've never questioned if it is too high or low.

I used the shoe sensor with the iPod touch for a year and now the 6th gen Nano for a year. During my transition from one to the other distances matched up nicely.

Hope that helped.

Can u use the shoe sensor with the current nano?

It doesn't need it. And I don't think the Nano would see it.